Plants perennial; cespitose, with short, thick, scaly rhizomes. Culms 80-500 cm tall, to 1.5 cm thick, reedlike, almost woody; internodes solid. Leaves cauline, evenly distributed, distichous; sheaths with tightly overlapping margins; ligules composed of a cartilaginous ridge subtending a line of hairs; blades broad, flat, deciduous at maturity, margins not cartilaginous. Inflorescences terminal, plumose panicles, 30-80 cm, exceeding the upper leaves; disarticulation above the glumes and between the florets. Spikelets laterally compressed; florets (2)4-10, bisexual, lowest florets sometimes only an empty lemma; rachilla internodes glabrous. Glumes 2, subequal, shorter than the lemmas, narrowly ovate, glabrous, membranous, 1-veined, acute; calluses obtuse, pilose; lemmas narrowly ovate, thinly membranous to hyaline, 3-veined, midveins glabrous, margins and lateral veins long pilose on the distal 2/3, apices bifid, shortly awned from between the teeth; paleas shorter than the lemmas, hyaline, 2-keeled. x = unknown, frequently reported as 10. Named after A.A. Reynaud, a French surgeon and botanist, who was already honored by Reynaudia, a genus of grasses from Cuba; hence the anagram Neyraudia.